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R M Riehl

Publications and source records attributed to R M Riehl.

At least 19 recordsLinked to original sources
PubMed1992

Application of the cavitron ultrasonic surgical aspirator (CUSA) for gynecological laparoscopic surgery using the rabbit as an animal model.

OBJECTIVE: To study the potential application of the cavitron ultrasonic surgical aspirator (CUSA) in gynecological laparoscopic surgery using a rabbit animal model. DESIGN: Twenty-six rabbits were prospectively randomized into two groups. Laparoscopically directed standard injuries were made on the randomly assigned horn and sidewall in all animals with the CUSA. Contralateral injuries were made with a contact neodymium-yttrium aluminum garnet (Nd:YAG) laser in group 1 and with bipolar cautery in group 2. Adhesion and inflammation scores were assessed for two animals in each group at 24, 48, and 72 hours, and seven animals in each group at 14 days. SETTING: University animal research facility. MAIN OUTCOME MEASURES: Adhesion and inflammation scores were compared between animals in the CUSA versus Nd:YAG study and the CUSA versus bipolar cautery at 14 days. RESULTS: No significant difference in uterine or sidewall adhesion scores was noted between the CUSA versus Nd:YAG or the CUSA versus bipolar cautery. Bipolar cautery produced significantly less inflammation on the uterine horn compared with the CUSA (3.0 +/- 0.2 versus 5.3 +/- 0.7, P = 0.0001), but no difference in sidewall inflammation was noted between the CUSA compared with bipolar cautery. No difference in inflammation was observed between the CUSA and the Nd:YAG laser. CONCLUSIONS: The bipolar cautery appears to be preferable to the CUSA for coagulation of uterine lesions, although dissection of the uterus is not possible with bipolar cautery. The CUSA and the Nd:YAG appear to be comparable for uterine horn dissection. Because the CUSA causes similar adhesion formation and tissue inflammation at the sidewall when compared with the Nd:YAG laser and bipolar cautery and may be less likely to damage blood vessels, ureters, or other collagen-rich tissues, the CUSA may represent a promising new surgical tool for laparoscopically directed peritoneal dissection.

Animals↗
PubMed1991

Nucleic acid binding characteristics of group A/B hnRNP proteins.

hnRNP proteins are primarily defined by their specific sedimentational, reconstitutional, and extraction properties and are presumed to be RNA binding. However, it is not clear whether all these proteins have RNA binding capabilities. Recently, using two monoclonal antibodies, fA12 and AC88, we reported that the abundance of a subclass of the highly basic A/B hnRNP proteins was specifically down regulated during terminal differentiation of human and murine cells in vitro. In this report we have examined the nucleic acid binding characteristics of this subclass and other members of the A/B hnRNP proteins in vitro. All members of class A/B hnRNP proteins appear to have similar but not identical nucleic acid binding characteristics. However, the subclass of proteins recognized by AC88 and fA12 exhibit stronger binding affinities and are shown to be highly selective in their binding to RNA vs DNA in vitro. These proteins also preferentially bind poly(U) RNA, suggesting that in vivo they may bind effectively to uridine rich motifs critical in pre-mRNA processing.

Animals↗
PubMed1991

Effects of clomiphene citrate and leuprolide acetate on luteal-phase hyperprolactinemia during ovarian stimulation with menopausal gonadotropins.

Hyperprolactinemia, a known modulator of reproductive function, occurs commonly in women undergoing ovarian stimulation with human menopausal gonadotropins (hMG). Clomiphene citrate (CC) and gonadotropin releasing hormone analogues (GnRHa), when administered during the luteal phase, attenuate the hyperprolactinemic response to hMG. We asked whether follicular-phase administration of CC and GnRHa, as employed clinically in women undergoing ovarian stimulation for in vitro fertilization or gamete intrafallopian transfer, would alter the incidence and severity of hMG-induced luteal-phase hyperprolactinemia. Seventy-five percent of all patients had at least one luteal prolactin level greater than 25 ng/ml, and 40% had mean luteal-phase prolactin levels greater than 25 ng/ml. The incidence of hyperprolactinemia was similar in pregnant and nonpregnant cycles. The incidence of hyperprolactinemia was similar for both the GnRH agonist-treated group and those given clomiphene citrate. The increase in mean luteal prolactin levels over the follicular-phase baseline level was significantly greater in the CC-treated group (P = 0.03). This was due to the significant suppression of follicular-phase baseline prolactin levels in patients receiving CC. We conclude that neither CC nor GnRHa administration in the follicular phase prevents luteal-phase hyperprolactinemia in women undergoing ovarian stimulation with hMG.

Clomiphene↗
PubMed1991

c-myc protooncogene polypeptide expression in endometriosis.

The c-myc protooncogene and its polypeptide product are important regulators of cell proliferation and differentiation, and ovarian steroids are believed to stimulate growth of various uterine cell types through altered expression of the c-myc gene. To determine whether c-myc expression may also be involved in the growth and development of endometriosis, we assessed c-myc expression in eutopic and ectopic endometrial tissue obtained from women undergoing surgery for endometriosis. Immunocytochemistry using a monoclonal antibody to the c-myc protein demonstrated positive staining of glandular and stromal cell nuclei, and cytoplasmic staining of glandular but not stromal cells in both eutopic and ectopic endometrium. These findings suggest that c-myc expression may be an important regulator of cell proliferation in endometriotic tissue.

Adult↗
PubMed1991

Immediately preovulatory levels of messenger ribonucleic acid for inhibin alpha-subunit are diminished in granulosa cells from successful in-vitro fertilization-embryo transfer.

Inhibin, a gonadal glycoprotein which suppresses pituitary gonadotrophin secretion, preferentially follicle stimulating hormone, has been extensively characterized. It consists of two covalently bound subunits, the alpha- and beta-subunits, encoded by separate genes. In this study, the expression of messenger ribonucleic acid (mRNA) for the inhibin alpha-subunit was studied by Northern blot analysis in granulosa cells of women undergoing in-vitro fertilization/embryo transfer (IVF/ET). Three patient groups were studied: women who failed to become pregnant (n = 11), women who became pregnant but experienced early spontaneous abortion (n = 3) and women who conceived normal ongoing pregnancies (n = 4). Granulosa cells were obtained at the time of follicle aspiration. Levels of alpha-subunit mRNA were 40% lower in patients establishing normal pregnancies than in those who failed to become pregnant or who spontaneously aborted. Thus, a relative diminution of immediately preovulatory levels of mRNA for inhibin alpha-subunit is a marker of success in clinical IVF/ET cycles. This marker of IVF/ET success can be related to previously established markers of success (increased follicular fluid oestradiol and decreased follicular fluid cyclic adenosine monophosphate) by known physiological mechanisms.

Adult↗
PubMed1991

Serum progesterone levels predict success of in vitro fertilization/embryo transfer in patients stimulated with leuprolide acetate and human menopausal gonadotropins.

Serum progesterone (P4) levels greater than 2.86 nmol/L (0.9 ng/mL) on the day of hCG administration are reportedly associated with decreased pregnancy rates in in vitro fertilization/embryo transfer (IVF/ET) cycles. To further assess this phenomenon we measured serial serum P4, LH, and estradiol levels in 115 consecutive patients undergoing stimulation for IVF/ET with midluteal leuprolide acetate and human menopausal gonadotropins. IVF/ET cycle outcome was retrospectively correlated with P4 levels on the day of hCG administration. Two critical breakpoints were identified, 1.27 nmol/L (0.4 ng/mL) and 286 nmol/L (0.9 ng/mL). Clinical pregnancies occurred in 9 of 18 patients in group I (P4, less than 1.27 nmol/L) compared to 11 of 81 patients in group II (1.27 less than P4 less than 2.86 nmol/L; P = 0.001) and 0 of 14 patients in group III (P4, less than or equal to 2.86 nmol/L) (P = 0.001). Eleven patients in group III had cryopreservation of embryos during that cycle. Six subsequently underwent frozen embryo transfer, and clinical pregnancies occurred in 2, both of whom have delivered. These findings demonstrate that even modest increases in serum P4 levels (greater than 1.27 nmol/L) are associated with reduced pregnancy rates in IVF/ET cycles. In addition, it appears that the mechanism may not exclusively involve poor oocyte quality.

Antineoplastic Agents↗
PubMed1991

Macrophage-conditioned media enhance endometrial stromal cell proliferation in vitro.

It has been hypothesized that the activated peritoneal macrophages of endometriosis, rather than being a response to ectopic endometrium, may contribute to its pathogenesis. This study attempts to define the effect of macrophage-derived growth factors on endometrial stromal cell growth in vitro, as well as the interaction between estrogen and these growth factors. Mouse endometrial stromal cells were prepared and cultured in either a serum-containing, insulin-free medium or a serum-free, insulin-containing medium, and the effects of adding 10% macrophage-conditioned medium on [3H]thymidine incorporation were assessed. Results indicate that macrophage-conditioned medium will increase incorporation in the presence of insulin but not in insulin-free media. Serum can substitute for macrophage-conditioned medium, but the two together show no additive or synergistic effect. The effect of estrogen on this system was determined, and results indicate that estrogen will perform the function of insulin, with an optimal concentration of 10(-10) to 10(-12) mol/L. Thus macrophage-conditioned medium appears to function as a competence growth factor, and estrogen (in appropriate concentrations) functions as a progression growth factor.

Animals↗
PubMed1990

Effects of gonadotropin-releasing hormone agonist and clomiphene citrate on estrogen/progesterone-induced hyperprolactinemia in monkeys.

The effects of follicular phase clomiphene citrate (CC) and two regimens of leuprolide acetate on estrogen-progesterone-induced hyperprolactinemia in nonhuman primates were studied. All groups received estradiol (E2) benzoate (12.5 micrograms intramuscularly on cycle days 2 to 33) and progesterone (P) (silastic implant for cycle days 14 to 33). A gonadotropin-releasing hormone agonist (GnRH-a) (Lupron 0.5 mg daily, TAP Pharmaceuticals, Chicago, IL) was administered from cycle day 2 to 14 in group II and from day 20 of the previous cycle until cycle day 14 in group III. Oral CC was given on cycle days 3 through 7 in group IV. No significant differences of mean E2 and P concentrations were noted between groups. Neither GnRH-a nor CC had an overall effect on E2/P-induced hyperprolactinemia. However, for the 5-day interval at the onset of the P treatment there was a significant increase in prolactin (PRL) secretion for group II (130.4 +/- 30.6) versus group I (53.9 +/- 3.3), group III (64.4 +/- 11.1), and group IV (68.8 +/- 14.3). This suggests that leuprolide may exert a delayed stimulatory effect on PRL secretion, or that complete suppression of the putative paracrine regulation of PRL stimulation may require more than 13 days of GnRH-a administration.

Animals↗
PubMed1990

Premature luteinizing hormone surges in menopausal gonadotropin-stimulated cycles in monkeys: lack of initiation by progesterone.

The occurrence of spontaneous luteinizing hormone (LH) surges in women receiving human menopausal gonadotropins (hMG) for in vitro fertilization-embryo transfer is a significant clinical problem. One hypothetical mechanism is that premature progesterone (P) secretion occurring in the high estradiol (E2) milieu produced by hMG triggers the spontaneous LH surge. To investigate this possibility, 11 rhesus and cynomolgus monkeys were stimulated with hMG. At maximal ovarian stimulation, monkeys were injected with 15 micrograms/kg P (n = 3), 30 micrograms/kg P (n = 3), or 1,000 IU human chorionic gonadotropin (hCG) (n = 5; controls). Blood for E2, P, and LH was drawn twice daily in the periovulatory period and daily before and after this period. Laparoscopy was performed after P or hCG injection. In the 6 monkeys receiving P, no LH surges were detected. Further, postinjection P profiles and laparoscopy showed no evidence of ovulation. Controls demonstrated laparoscopic and hormonal evidence of ovulation. These findings suggest that P does not trigger LH surges in hMG-stimulated cycles.

Animals↗
PubMed1990

Effects of tamoxifen on corpus luteum function and luteal phase length in cynomolgus monkeys.

Previous data in nonhuman primates have demonstrated that tamoxifen prolongs the luteal phase without altering reproductive hormone levels. A small study in humans found no effect on menstrual cycle length, but an increase in luteal ovarian steroid levels. In view of these conflicting results, we studied the effect of tamoxifen on corpus luteum (CL) function in monkeys (n = 20). Blood was obtained daily beginning cycle day 8, and sera assayed for estradiol (E2), progesterone (P), luteinizing hormone, and follicle-stimulating hormone. Four days after the midcycle E2 peak, laparoscopy confirmed CL formation, and the animals were administered (1) lactose (n = 7), (2) tamoxifen, 0.5 mg.kg-1.d-1 (n = 6), or (3) tamoxifen, 3.0 mg.kg-1.d-1 (n = 7) for 12 consecutive days. Serum collection continued until cycle day 50 or menses, whichever came first. Results indicate a biphasic response among tamoxifen-treated animals, with 7 of 13 developing prolonged luteal phases. There was, however, no significant difference in luteal phase length among the three groups, although when the two groups given tamoxifen were combined, the difference in luteal phase length versus controls approached significance. No differences were found among peak P levels, mean luteal phase P levels, or mean luteal phase gonadotropin levels. No variables were found to correlate significantly with luteal phase length. These results suggest that luteal phase administration of the antiestrogen tamoxifen does not alter pituitary gonadotropin secretion or CL function. However, tamoxifen does prolong luteal phase length in a subset of monkeys, perhaps via a direct effect on the endometrium.

Animals↗
PubMed1990

Cocaine disrupts estrous cyclicity and alters the reproductive neuroendocrine axis in the rat.

Although a common drug of abuse, cocaine's effects on cyclic reproductive functions and the neuroendocrine systems regulating these functions have not been studied. Here, we report the effects of cocaine on (1) estrous cyclicity and ovulation rates and (2) the stimulated in vitro release of hypothalamic GnRH and aminergic neurotransmitters directly involved in regulating or modulating GnRH release. Within 7 days of treatment with 10 mg kg-1 day-1 of cocaine HCl subcutaneously, rats demonstrated significant estrous cycle irregularity including repetitive days of estrus and prolonged periods of diestrus. After 6 weeks of treatment, cocaine-treated rats exhibited a 44.3% decrease in ovulation rates. For the in vitro studies, bilaterally ovariectomized rats were injected with cocaine (10 mg kg-1 day-1) or with saline for 2 weeks. Each rat received estradiol benzoate (50 mg kg-1 day-1 s.c.) for 2 days before sacrifice. Hypothalamic slices were prepared, placed in 0.1 ml microchambers and perfused with modified Krebs buffer (pH 7.4) using a programmable perfusion system. Basal release of norepinephrine (NE) and serotonin (5HT) was significantly increased in the cocaine-treated group versus controls. Ten-minute pulses of 10(-7)M progesterone (P4) increase NE and 5HT, but not dopamine (DA), release in the saline-treated group. In contrast, pulses of P4 increased NE, but not 5HT or DA, in the cocaine-treated rats. Ten-minute pulses of 0.1 microM NE increased GnRH release in both saline- and cocaine-treated rats. However, the response to pulsed NE was significantly attenuated in the cocaine-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Gamete intrafallopian transfer vs superovulation with intrauterine insemination for the treatment of infertility.

Superovulation with intrauterine insemination (SO-IUI) has been suggested as an alternative to gamete intrafallopian transfer (GIFT), despite the absence of controlled or comparative trials. We retrospectively analyzed all GIFT and SO-IUI cycles performed concurrently from January 1985 to August of 1987 at a single university center. Pregnancy rates were significantly better for GIFT than SO-IUI (P less than 0.001), with an odds ratio of 3.25 (P = 0.001). Stepwise multiple logistic regression identified factors that correlate with pregnancy: absence of endometriosis (P = 0.05), infertility less than 3 years' duration (P = 0.002), TMS greater than or equal to 30 X 10(6) (P = 0.005), and treatment with GIFT rather than SO-IUI (P = 0.001). These data give a first approximation of the increased efficacy of GIFT versus SO-IUI and provide valuable insight into significant confounding variables to be considered when planning a randomized, prospective trial to evaluate these techniques.

Adult↗
PubMed1989

Gonadotropin-releasing hormone antagonists attenuate estrogen/progesterone-induced hyperprolactinemia in monkeys.

Previous studies have documented that exogenous gonadotropin-releasing hormone (GnRH) stimulates prolactin (PRL) secretion and augments thyrotropin-releasing hormone-induced PRL release. Further, the concomitant pulsatile release of PRL and luteinizing hormone (LH) suggests that GnRH may be an important regulator of PRL release in certain physiologic states. The authors explored this possibility by evaluating the effect of a GnRH antagonist ([Ac-pClPhe1, pClPhe2, DTrp3, DAla10]-GnRH; GnRH-antagonist) on PRL secretion in monkeys with induced hyperprolactinemia. Monkeys were given estradiol (E2) benzoate 25 mg/kg intramuscularly (IM) on cycle days 1 to 28, and a 3-cm progesterone (P) silastic capsule was placed on cycle day 15 and removed on day 28. On cycle days 15 to 28, monkeys were given IM injections of 1 mg/kg GnRH-antagonist (n = 3), 2 mg/kg GnRH-antagonist (n = 3), or vehicle (n = 3). Daily blood samples were assayed for E2, P, and PRL. The degree of PRL elevation was calculated as percent increase in area under the curve for days 15 to 28 when compared with days 1 through 14 (baseline). Luteinizing hormone levels were calculated similarly. Results indicate a dose-dependent effect of GnRH-antagonist on PRL secretion, with the larger dose producing a significantly lower hyperprolactinemic response, as well as a decline in LH. Thus, GnRH-antagonist attenuates induced hyperprolactinemia in a dose similar to that which suppresses LH release. These findings suggest that GnRH is a physiologic regulator of pituitary PRL secretion. In addition, GnRH analogs may be of benefit in controlled ovarian hyperstimulation by attenuating gonadotropin-induced hyperprolactinemia, thereby reducing potential adverse effects on fertility.

Animals↗
PubMed1989

Platelet-activating factor in human luteal phase endometrium.

Platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) is one of the most potent mediators of vascular permeability. PAF levels change in the rabbit endometrium just prior to implantation, which suggests that PAF may be a key substance transducing preimplantation embryonic signals. To study whether PAF was present in the human endometrium, and if so, to determine the cellular origin and hormonal regulation of endometrial PAF, specimens were obtained from 14 women (aged 23-42 yr) undergoing elective hysterectomy during the luteal phase of the cycle (plasma progesterone levels greater than 2 ng/ml). No specimens were taken from women with malignant uterine pathology. Stromal cells and epithelial glandular cells were separated by collagenase and DNAse digestion, and then cultured to confluence in vitro in medium 199. Radioimmunoassays of prostaglandin F (PGF) and prolactin in the culture media were used to confirm cell type and viability. PGF release into the culture medium from stromal cells was low (control 1.52 +/- 0.20 ng/ml), and unchanged by hormone treatment. In contrast, release of PGF from unstimulated glandular cells was 6.05 +/- 0.52 ng/ml, and was significantly increased (p less than 0.05) by estradiol or progesterone plus estradiol, to 12.17 +/- 1.67, and 8.60 +/- 0.81, respectively. Progesterone alone was without effect. Prolactin was secreted by stromal cell cultures, increasing steadily from 24 to 120 h. The levels in the medium were increased by progesterone. PAF activity was assessed by rabbit platelet aggregation and serotonin-release bioassays after lipid extraction and separation by thin-layer chromatography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Laser-induced fluorescence of ectopic endometrium in rabbits.

Endometriosis appears under a wide array of morphologies, and early microscopic disease escapes visual inspection. To improve endoscopic diagnosis, we studied the optical properties of ectopic endometrial tissue, in particular laser-induced fluorescence. Photosensitive drugs were used to obtain a selective signal. Five groups of four rabbits underwent surgical induction of endometriosis and were treated with estrogens for 5 weeks to stimulate growth of the implants. Intramuscular injections of vehicle, tetracycline hydrochloride, 6-demethyl-6-deoxytetracycline hydrochloride, tamoxifen citrate, and clomiphene citrate were given 24 hours before exposure of the tissues to argon-ion laser (351.1 nm + 363.8 nm; power density approximately 1.5 mW/cm2). Fluorescence was documented on photographic film. In controls, peritoneum and ovaries showed a dim, white-yellow fluorescence, whereas other tissues exhibited blue tones. Animals treated with tetracycline hydrochloride or tamoxifen citrate showed yellow fluorescence of active endometrial implants and the uterotomy site. Two implants, histologically without viable glandular tissue, did not fluoresce. Treatment with 6-demethyl-6-deoxytetracycline hydrochloride yielded signals of lower intensity. Clomiphene citrate caused fluorescence of the uterotomy site only. This experiment demonstrates that, of the compounds used, tamoxifen is the best selective photoenhancer for endometriotic implants and clomiphene is best for the uterotomy site. This study establishes the potential of these drugs for photoradiation diagnosis and possible treatment of diseases involving ectopic endometrium.

Animals↗
PubMed1988

The effects of environmental stress on steroid receptor levels and steroid-induced morphogenesis in Achlya ambisexualis.

Incubation of Achlya ambisexualis at elevated temperature (heat shock) or in the presence of sodium arsenite resulted in an inhibition of steroid hormone-induced responsiveness. The effect of heat shock was time- and temperature-dependent and more severe than the effect of sodium arsenite. Incubation at 37 degrees C for 30 min completely abolished the steroid-induced response and full recovery was not observed until 6 h after a return to the normal growth temperature of 22 degrees C. Heat shock and arsenite treatment had no effect on the cellular uptake of the steroid hormone, but heat shock resulted in a time- and temperature-dependent loss in the cellular level of steroid receptors. In contrast, arsenite treatment had little effect on the concentration of steroid receptors. However, both heat shock and arsenite treatment produced a long-term (4 h) and transient (1 h) inhibition of total protein synthesis, respectively. The recovery of steroid-induced responsiveness following heat shock was observed after both protein synthesis and steroid hormone receptor levels had returned to normal values.

Fungi↗
PubMed1985

A 90,000-dalton binding protein common to both steroid receptors and the Rous sarcoma virus transforming protein, pp60v-src.

Previous studies have shown that the avian progesterone receptor, when in the nontransformed 8 S state, is complexed to another cellular protein having a molecular weight of 90,000. In this report, we show that this receptor-binding protein is indistinguishable from the 90,000-dalton protein which associates in a complex with the Rous sarcoma virus transforming protein, pp60v-src. This identity was established by the following criteria. 1) Monoclonal antibodies directed against the pp60v-src-associated 90-kDa protein recognized the 90-kDa progesterone receptor binding protein in an immunoblot assay. Conversely, monoclonal antibodies that recognize the progesterone receptor binding protein bind to the 90-kDa protein which complexes with pp60v-src. 2) Peptide maps prepared from the 90-kDa proteins immunoprecipitated from chicken cells with monoclonal antibodies directed against either the 90-kDa receptor binding protein or the 90-kDa pp60v-src-associated protein were indistinguishable. 3) Preincubation of the progesterone receptor complex with monoclonal antibodies prepared against the pp60v-src-associated protein caused a shift in the sedimentation of the progesterone receptor. Previous studies have established that the pp60v-src-associated protein is indistinguishable from one of the major heat shock proteins which are induced under a variety of stress conditions in eukaryotic cells. These present studies implicate a new role for this 90-kDa protein in the action of steroid hormones.

Animals↗